Endless track devices for laying cables and the like

ABSTRACT

A pair of opposed endless track devices have adjacent branches whose links cooperatively engage a cable therebetween and advance the cable with the links. The links travel in rails and form chambers therewith in which pressure fluid is supplied to force the links into engagement with the cable while advancing the links and cable therewith.

United States Patent [56] References Cited UNITED STATES PATENTS2,792,930 5/1957 Graham....

[72] Inventor Bernard Francoh Maurice Courret Toulon, France [21 Appl.No. 889,139

22 WU un 6 22 Z 2,935,178 5/1960 Lutcke.... 3,024,956 3/1962 Gretterm.

[22] Filed Dec.30,l969 [45] Patented Nnv.9, I971 73 Assi nee EtatFrancala De atlon Mlnhterielle pour l 1 8 L'Arnienent kg FOREIGN PATENTS3/1965 France Perle, France m m Wm w h N& 0 QR r 3 MW i, We 0" W mm 8 69 1 v o 1 am mnu FI- .w n O n P nun BBB [54] ENDLESS TRACK DEVICES FORLAYING CABLES AND THE LIKE ABSTRACT: A pair of opposed endless trackdevices have adjacent branches whose links cooperatively engage a cabletherebetween and advance the cable with the links. The links travel inrails and form chambers therewith in which pressure fluid is supplied toforce the links into engagement with the 2 ,l nmnn l HhZ M2 11 Claims, 7Drawing Figs.

[52] US. (11...... [5|] Int. [50] Field of cable while advancing thelinks and cable therewith.

PATENTEDNUVI 9mm j 3, 1 40 sum 1 or 4 PATENTEUNUY 9|B7| I 3,618,840

sum 2 OF 4 I T- will F 6 2 7/\ ,2

Ill 5 5 i I *4 L ,5- \,l N 2 i A A +/4 H f nude BRIEF SUMMARY OF THEINVENTION The invention relates to endless track a cable or the like.

Such endless track devices Navy, for hauling or restraining as pipes,towing lines, etc.

- These devices comprise two endless tracks composed of continuouschains arranged on both sides of the site to be occupied by the objectto be laid.

Contact of the tracks with such object is obtained by ad justably spacedlongitudinal rails in which the links of the chains are guided duringforward advance by driving sprockets on which the chains travel.

Such an arrangement leads toconsiderable stresses and friction, on therails and on the tracks themselves and especially to very great strainon the link pins.

An object of this invention is to allowing uniform distribution ofstresses over the whole length tact with the object to be laid.

For this purpose, according to the invention, rails and track links areso arranged as to form chambers in which pressure fluid is supplied toforce the links into contact with the object to be laid or hauled and toadvance the links and the object therewith.

By this arrangement the links are subjected, during their travel betweenthe rails, to a force which is resolved into one component normal to theobject to be laid or hauled, assuring proper grip thereon, and a secondcomponent in the direction of movement of the track.

This resolution of the total force into simple forces brings about areduction of internal strains and consequent decrease in weight andinitial cost of the arrangement as well as a reduction in operationcosts.

Furthermore, the gripping and tractive forces are exerted by the linksthemselves, which canthen simply travel on idler pulleys. The tracks nolonger are subjected to the tractive effort and their pin joints arerelieved.

A single, generally hydraulic, fluid serves for producing the grippingand tractive efforts. Braking can be obtained by reducing the pressureof the fluid, which provides a further simplification.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic plan view ofan endless track device according to the invention,

FIG. 2 is a view of a portion of the device on a showing the drivethereo FIG. 3A is a section taken on line A-A of FIG. 2,

FIG. 3B is a section taken on line BB otFlG. 2,

FIG. 4 is a perspective view of the body of a track link,

FIG. 5 is a similar view of the body frame, and

FIG. 6 is a section on a larger scale of a portion of the links showingthe waterproof sealing arrangement for the track.

DETAILED DESCRIPTION In the embodiment shown in the drawing, thetractive or hauling device essentially comprises two endless tracks 1arranged on both sides of a towline 2 to be hauled, the line beingclasped between links of the tracks 1 (FIG. I).

The tracks I are formed by links 3 joined to each other by pins 4 toform endless chains riding on free, idler sprockets 5 mounted on axles 6parallel to pins 4.

In their travel, the links contact the towline, and the tracks I areguided by longitudinal blocks formed by spaced parallel rails 7 whosespacing can be adjusted by a cross coupling 8 which for example may behydraulic cylinders or transverse screws.

As can be seen more clearly in FIGS. 2, 3A and 38, each link engages thetowline 2 by means of a flange 9 shaped to devices for advancing areused, particularly in the cables or similar objects such minimize thesestresses by the holding and tractive of the sides of the tract in conthesupport larger scale with one another laterally conform to the towline,and made of rubber or similar comparatively hard elastomer of a SHOREhardness greater than 60 Towline 2 is of the faired type, with a shell10 surrounding a load rope II and containing a hole 12 for fittings 13as shown in FIG. 38.

With such construction, flange 9 is substantially J-shaped to enclaspthe part of the shell adjacent the load rope.

Flange 9 rests on a pad 14 secured in a shell 15. The pad 14 is made ofrubber or a similar soft and resilient substance.

Pad 14 performs a threefold function, namely:

a. by reason of its own resilience, it sustains an initial pressure gripon the towline;

b. it compensates for irregularities of thickness in the towline;

c. the pad undergoes warping to resist shear force in the lengthwisedirection, and compensate for variation in length of the towlineoccurring between its entry and exit from the endless tracks by thefluctuation in tension to which the towline is subjected at these twopoints.

Pad 14 is embedded at its base in the shell 15 which, as shown in FIG.4, has a U-shaped channel 16 for housing the pad.

The shell 15 is composed of a metal frame I7 onto which a thermosettingsynthetic plastic is molded.

The lateral faces of the shell are engaged with slight friction in theguide rail 7 which has a lengthwise U-shaped channel for this purpose.

The rails include flanges towline 2 as shown in FIG. 38.

For the joining of the links, shell 15 carries lugs 19 and 20 (FIG. 4)in which suitable extensions of frame 17 are moulded (FIG. 5).Successive chain links are joined by pins 4.

Links 3, as shown particularly in FIGS. 2 and 3, include a longitudinalrib 21 on the outer side flanked by two hollows or chambers 22 whichalong their length are of approximately sinosoidal shape, the two crestsbeing located at the respective ends of the link. Frame 17 extends intorib 21.

This rib becomes a supporting and friction surface when in contact withthe bottom of rail 7. The outer surfaces of the flanges on the linkprevent the link from tilting under the reaction of the towline on theflanges 9 and also guarantee sealing and tightness laterally in relationto chambers 22 defined on both sides of the rib 21 by the link and thewalls of the rail.

At the forward end of each link relative to the direction of motion ofthe endless track, a transverse sealing arrangement consisting of asealing member 23 seated in groove 24 of the link body is provided.Groove 24 extends behind the sealing member 23 to chamber 22 throughchannels 25 machined in the link, as shown in FIG. 6.

At the other or trailing end of each link there are provided grooves 26to form decompression chambers.

As will be evident in FIGS. 1, 2 and 3A, the chambers 22 are used forpropelling or restraining the endless tracks and for this purpose eachof the rails 7 is provided with spaced chests 27 for the inflow andoutflow of a pressure fluid.

The spacing between two consecutive chests 27 is established such that awhole number of links equal in number to the chests extends in the spacebetween the extreme chests 27a, 27b, so that in this way there is asmooth and steady shift from one link to the next, between each link andthe chest opposite it, which provides a practically steady stress on theendless tracks 1.

Each chest 27 comprises two identical chambers 28 (FIGS. 2 and 3A)separated by a bafile 29 equal in thickness to rib 21 against which thebafile is engaged. Chambers 28 are rectangular in section perpendicularto the rail 7 and they link up on the walls of the rail.

The chambers 28 contain rollers 30, whose thickness is equal to thewidth oi chambers 22, while their diameter is substantially twice thernaximum depth of the chambers 22.

In the bottom of each chamber 28 is an inlet channel 31 for pressurefluid. A corresponding communicating channel 32 to 18 to provideprotection for chamber 22 for this fluid is machined in the front wallof chest 27 at chambers 2%.

In the rear walls of chest 27 at chambers 2h, outflow channels 33 areformed on both sides of bafile 29.

In operation, the pressure fluid enters channels 32 and flows intochambers 22 esmhlished between the rail and the link, and the pressurefluid pushes the rollers 34) rearwards to seal securely at 34 on therear wallof chat 2? as shown in FIG. 2. The rollers 30 thus movetransversely, as the track advances longitudinally, by rolling along thesinosoidal surface of the chambers 22. The rollers divide each chamber22 into forward and rearward compartments which vary in volume duringadvance of the track.

n the one hand, the pressure fluid applies the link against the towline,and on the other hand it exerts a force on that link urging it to movein the direction shown by arrow f (FIG. 2). During this time, the fluidlocated in chambers 22 at the back of the rollers 30 flows out throughchannels 33.

End chests 27a and 27b include only an outflow or an inflow channel asthe case may be.

The movement of the endless track is facilitated on one side by theseparation of rib 21 which no longer rubs on the bottom of the rail, andon the other by the fact that the rollers 30 roll on the back of thelinks and therefore do not rub thereagainst with friction.

On the contrary, when the pressure drops, the track, under the resilientforce of 14 is pressed against the bottom of the rail thus providingefficient braking. For this purpose the coefficient of friction betweenthe rail and the links is of advantage since the static tractive forceon the towline may then be borne without movement.

The tension of the return side of the track can be zero or set to somefixed value to facilitate operation.

Chests 27 are supplied under balanced pressure and variable dischargesto adjust the running speed of the towline in its travel. The number ofchests can be adjusted as required and adapted to the requirements ofdiflerent particular cases.

What is claimed is:

l. Apparatus for advancing a cable comprising at least one moveableendless track device for engaging a cable to advance the same lengthwisethereof, said track device comprising a plurality of links and a railsupporting said links and defining chambers therewith, and means forsupplying a pressure fluid to said chambers to apply the links againstthe cable, said chambers being so formed that the pressure of the fluidtherein produces a longitudinal force on the links to advance the linksand the cable therewith.

2. Apparatus as claimed in claim 1 comprising a second endless trackdevice opposed to the first to clamp the cable between the links thereofto advance the cable.

3. Apparatus as claimed in claim 2 wherein each link has at least onehollow which forms with the associated rail in respective of saidchambers, said means for supplying pressure fluid comprising an inletand an outlet, and means dividing each said chamber into twocompartments which vary in volume during advance of the track, onecompartment being in communication with said inlet and the other incommunication with said outlet.

4. Apparatus as claimed in claim 3 wherein said hollow is approximatelysinusoidal in shape, said means dividing each chamber into twocompartments comprising a transversely displaceable member engaging eachlink along said hollow.

5. Apparatus as claimed in claim 4 wherein said transverselydisplaceable member is a roller having a diameter greater than themaximum depth of the hollow, said means for supplying pressure fluidcomprising a chest with spaced walls and provided with said inlet andoutlet, said roller being guidably movable between said walls.

6. Apparatus as claimed in claim 4 wherein said rail has a U- shapecross section, each said link having outer surfaces in frictionalengagement with said rail.

7 Apparatus as claimed in claim 6 wherein each link has two of saidhollows and a central rib between said hollows, said rib frictionallyengaging said rail upon cessation of supply of pressure fluid, each saidhollow having one said transversely displaceable member therein.

8 Apparatus as claimed in claim 3 wherein said means for supplyingpressure fluid comprises a plurality of spaced chests along said rail,each chest having one said inlet and one said outlet, said chests beingspaced such that a plurality of links equal in number to the number ofchests are disposed between the endmost chests.

9 Apparatus as claimed in claim 1 wherein each link comprises a rigidbody supported by said rail, a flange conforming to the shape of thecable for engaging the same, and a resilient pad supporting the flangeon the body.

10. Apparatus as claimed in claim 9 wherein said link comprises a frameand a molded covering on said frame of synthetic plastic material.

11. Apparatus as claimed in claim 1 wherein each said link has a forwardend and a rearward end relative to the direction of travel of the track,and means at the forward end of each link forming a watertight seal withsaid rail for the associated chamber.

I! 4 8 II a

1. Apparatus for advancing a cable comprising at least one moveableendless track device for engaging a cable to advance the same lengthwisethereof, said track device comprising a plurality of links and a railsupporting said links and defining chambers therewith, and means forsupplying a pressure fluid to said chambers to apply the links againstthe cable, said chambers being so formed that the pressure of the fluidtherein produces a longitudinal force on the links to advance the linksand the cable therewith.
 2. Apparatus as claimed in claim 1 comprising asecond endless track device opposed to the first to clamp the cablebetween the links thereof to advance the cable.
 3. Apparatus as claimedin claim 2 wherein each link has at least one hollow which forms withthe associated rail a respective of said chambers, said means forsupplying pressure fluid comprising an inlet and an outlet, and meansdividing each said chamber into two compartments which vary in volumeduring advance of the track, one compartment being in communication withsaid inlet and the other in communication with said outlet.
 4. Apparatusas claimed in claim 3 wherein said hollow is approximately sinosoidal inshape, said means dividing each chamber into two compartments comprisinga transversely displaceable member engaging each Link along said hollow.5. Apparatus as claimed in claim 4 wherein said transverselydisplaceable member is a roller having a diameter greater than themaximum depth of the hollow, said means for supplying pressure fluidcomprising a chest with spaced walls and provided with said inlet andoutlet, said roller being guidably movable between said walls. 6.Apparatus as claimed in claim 4 wherein said rail has a U-shape crosssection, each said link having outer surfaces in frictional engagementwith said rail.
 7. Apparatus as claimed in claim 6 wherein each link hastwo of said hollows and a central rib between said hollows, said ribfrictionally engaging said rail upon cessation of supply of pressurefluid, each said hollow having one said transversely displaceable membertherein.
 8. Apparatus as claimed in claim 3 wherein said means forsupplying pressure fluid comprises a plurality of spaced chests alongsaid rail, each chest having one said inlet and one said outlet, saidchests being spaced such that a plurality of links equal in number tothe number of chests are disposed between the endmost chests. 9.Apparatus as claimed in claim 1 wherein each link comprises a rigid bodysupported by said rail, a flange conforming to the shape of the cablefor engaging the same, and a resilient pad supporting the flange on thebody.
 10. Apparatus as claimed in claim 9 wherein said link comprises aframe and a molded covering on said frame of synthetic plastic material.11. Apparatus as claimed in claim 1 wherein each said link has a forwardend and a rearward end relative to the direction of travel of the track,and means at the forward end of each link forming a watertight seal withsaid rail for the associated chamber.